Conventionally, there is known a wireless Local Area Network (LAN) implemented by connection among computers through wireless communications based on the IEEE 802.11 standard and the like in a local area such as an office. According to the wireless LAN, it is possible to implement, for example, a network making use of portability that is the greatest advantage of a notebook personal computer (hereinafter referred to as “notebook PC”) that have become widespread in recent years. In order to use such a wireless LAN through a notebook PC, the notebook PC needs to have an antenna for wireless communication and a wireless system including a communication module that executes communication processing based on the IEEE 802.11 standard and the like. Therefore, in recent years, a notebook PC that contains such a wireless system has appeared in the market (for example, see Japanese Patent Laid-open Publications No. 2000-341018, No. 2002-207535, No. 2004-015246 and No. 2006-052471).
Meanwhile, besides the above-described wireless LAN, there is a wireless Personal Area Network (PAN) implemented in an area smaller than that of the wireless LAN, such as an interconnection between a portable telephone and a notebook PC through wireless communication. In late years, there have been introduced a notebook PC that contains, in addition to the wireless system for the wireless LAN, a wireless system compliant with Bluetooth (registered trademark) that is an example of the communication standards of the wireless PAN. Further, in the field of notebook PCs, there is a movement for making a notebook PC contain: a wireless system for a wireless Wide Area Network (WAN) implemented in an area wider than that of the wireless LAN; and a wireless system for receiving the so-called “one-segment broadcasting” that has been a focus of attention as a simple version of the Digital Terrestrial Television Broadcasting. For this reason, there is a trend to increase the number of wireless systems built in a notebook PC.
An antenna for wireless communication is indispensable for a wireless system. Although the sizes of antennas have become smaller than before, it is still necessary to provide a space large enough to house an antenna. Therefore, finding room for housing an antenna is a concern when attempting to provide a notebook PC with a built-in wireless system. Meanwhile, the recent increase in the number of wireless systems built in a notebook PC has increased the number of built-in antennas. Further, if an antenna is carelessly disposed in a notebook PC, radio waves received by and transmitted from the antenna may electromagnetically interfere with an internal circuit, making it more difficult to provide a space for housing an antenna, which is already made difficult by the increase in the number of built-in antennas.
Providing a notebook PC with an additional space dedicated to housing of an antenna is a way of appropriately housing the antenna while avoiding electromagnetic interference. However, such a way increases the size of the notebook PC, impairing the portability.
Incidentally, the difficulty of providing a space for housing an antenna has been described so far by taking the notebook PC as an example. However, this is a problem that not only occurs in the notebook PC but also occurs in, for example, a Personal Digital Assistant (PDA) with a built-in wireless system or commonly occurs in any types of electronic device that generally meet this requirement.